Lighting fixture



oct. 19, 1943. P, ZAMPOL y 2,332,040

LIGHTING FIXTURE Filed Au- 27, 1941 :Snventor Gttornegs Patented Oct.19, 1943 LIGHTING FIXTURE Peter Zampol, Pontiac, Mich., assignor toYellow Truck & Coach Manufacturing Company, Pontiac, Mich., acorporation of Maine Application August 27, 19441, Serial No. 408,422 I2 Claims. (Cl. 24o- 7.35)

My invention relates to' a lighting fixture such as is used on passengermotor coaches.

In the design of commercial passenger vehicles considerable attentionmust be given to the interior lighting. The lighting must be so designedas to give adequate illumination in the reading zone without being sobright as to cause glare. It is likewise desirableA for the sake ofeconomy to furnish the desired lighting at a minimum of expense. Ifpossible, therefore, the lighting for the coach interior should be suchthat one light source will supply each two-passenger seat. Having allthese requirements in mind, it is further desirable to provide alighting xture which has a pleasing appearance.

It is the object of my invention t provide a lighting xture which may beused for the interior of commercial passenger vehicles to satisfy theforegoing requirements.

More specifically, it is the object of my invention to provide alighting fixture for motor coaches in which a properly designed lensdirects the rays of a single source of light in such a manner as tofurnish illumination in the reading zone for a two-passenger seat. Thellens of this invention has opposed cylindrical surfaces in which theaxes of the cylinders forming the surfaces are disposed at substantiallyright angles to each other. The lens is so located with respect to thepassenger seat that the axis of the cylinder having the greatercurvature is substantially parallel to the long axis of the seat. Thelight pattern thus formed is generally elliptical in shape, havingblight spots near the foci of the ellipse.

Figure 1 of the drawingshows a passenger vehicle provided with lightingfixtures made according to my invention.

Figure 2 is a View with parts broken away and in section substantiallyon line 2--2 of Figure 1.

Figure 3 is a llongitudinal section substantially online 3-3 of Figure2.

Figure 4 is a detail view with parts broken away and in section showingthe construction of the spacer which is disposed between adjacentexternal units of the fixture.

Figure 5 is a view in perspective of the lens used in the lightingxture.

Figures 6 and 7 are views in elevation and plan respectively of amodified lighting fixture using the lens of my invention.

Referring now to the drawing in detail, IIl indicates a passenger motorcoach provided with forwardly facing seats I2, each of which has a longaxis I2a. In the illustration, axis I2a is substantially perpendicularto the long axis of the side of the trough-like member 22.

vehicle. To the head lining I4 above the row of seats I2 is secured apair of opposed generally J-shaped clips I6. These clips may be made ofany suitable resilient material. The downwardly extending resilientmembers of these clips engage and removably hold in place a support I8.Support I8 is provided at its edges with parallel beaded channels 20.The beads of channels 20 cooperate with the downwardly extendingresilient members of clips I8 as best indicated at Figure 2. Secured inthe channels 20 are the edges of a trough-like or generallychannel-shaped cylindrical member 22. Member 22 may be made of anysuitable light pervious material such as glass or any of the moldedplastics now available. The light transmitting plastic commerciallyknown as Lucite has been found very satisfactory.

Spaced along support I8 I provide recesses 24 which serve as reflectorsand mounting means for light bulbs 26. The-spacing of bulbs-26 shouldcoincide with the spacing of seats I2 with the bulb disposed above theseat space so as to illuminate the reading zone of the seat space. Ithas been found desirable to provide member 22 in sections. Thesesections may be of any desired length but I prefer to provide two suchsections for each light source, having one section disposed immediatelybeneath each light source with the intervening space occupied by anothersection of member 22. Adjoining sections of member 22 are spaced bysubstantially semi-circular strips 28. Strips 28 are generally T-shapedin cross section as seen in Figure 4. These strips may also be made of asuitable molded plastic. It may be pointed out here that rather pleasingand sometimes striking ornamental effects may be obtained by thejudicious choice of colors ofthe molded plastics used for members 22 and28. It'will generally be found preferable to make member 22 of a whitetranslucent material which will glow along its entire length with brightspots spaced along its length according to the location of the lightsources. Spacer members 28 may likewise be white translucent members buta decorative eiect may be obtained by making spacers 28 of coloredtranslucent plastics. A generally L-shaped molding 30 may be secured tohead lining I4 on each Molding 30 serves to conceal the holding meansfor support I8 and trough-like member 22 and may also add to theornamental eifect of the fixture as a whole. For example, a pleasingeiect is obtained by making moldings 30 of chrome plated sheet metal.

The lens 32 of my invention is shown in perspective in Figure 5. As isreadily seen from Figures 2, 3 and 5, this lens has opposed surfaceswhich are formed by substantially circular cylinders the axes of whichare substantially at right angles. In the illustrationa'the curvature ofAone of these cylinders is substantially equal to the inside curvatureof member 22. The curvature of the other cylinder is considerablygreater. The difference is readily seen by reference to Figures 2 and 3.This arrangement of opposed cylindrical surfaces with one surface havinga greater curvature than the other gives a generally elliptical lightpattern with concentrations of light near the foci of the ellipse. By acareful proportioning of the curvature of the Y two surfaces these twoconcentrations of light may be spaced to coincide with the4 readingzones of two passengers seated side by side on one of the seats I2., Itwill be found that the light thus the like, resulting in greatereye-comfort to the driver as well as the passengers, The light patternproduced by this lens is indicated in dotted lines in Figure 1. It hasbeen found that the surface of lens 32 whose cylinder is substantiallyparallel to the longitudinal axis of the seat should have a curvaturewhich is in the vicinity of once and one half to twice the curvature ofthe cylinder whose axis is substantially perpendicular to the long axisof the seat. This 2 or 11/2 to 1 ratio is given merely to indicate theorder of magnitude of the ratios. More specifically, a ratio of 17 to 10has been found satisfactory.

It will not always be desirable to use the elongated member 22 made upof aligned short sections as shown in'Figures l to 4. Figures 6 and 7illustrate a modified lighting fixture with which lens 32 may be used.In these two gures a light pervious member 34 which may be cylindricalin cross-section is held in place by a retaining frame I6. Cover member34 is provided with a peripheral flange 38 which cooperates with ashoulder 40 on frame 3l. Frame 38 may be held in place on the headliningby screws 42 or any other suitable fastening means.

Lens 32 may be cemented in place in members 22 or 34 by any suitablelight pervious cementing material such as Canada balsam. However, anyother satisfactory means of securing lens 32 may be used. It may befound desirable. for example, w mold the plastic of which member 22 or34 may be made directly about lens l2.

The lighting fixture comprising my invention is not necessarily limitedto use in vehicles. It may be used in any application presentingproblems and requirements similar to those found in motor coachlighting.

I claim:

1. In a lighting fixture for application to the ceiling of a bus orother vehicle, the combination of a longitudinally extending support, alight source secured to said support intermediate the ends of saidsupport, a longitudinally extending light pervious member which issubstantially semicylindrical in cross section having the opposite edgesthereof secured to said support and constituting a light transmittingcover for said light source, and a light( concentrating! lens mountedwithin said cover member intermediate the ends of said member andadjacent said light source, said lens having the opposite surfacesthereof formed by two intersecting cylinders disposed with their axessubstantially at right angles to each other with one of said surfacesconforming to and fitting within the inner surface of said cover member.

2. The combination set forth in claim 1 in which the curvature of thelens surface which conforms to the adjacent surface of the cover memberis smaller than the curvature of the opposite lens surface to therebyproduce a relatively strong concentration of light rays within agenerally elliptical predetermined area having its major axis extendingltransversely of the vehicle.

PETER ZAMPOL.

